Fraunhofer's 3D printed exploration spiders are intended for use "as an exploratory tool in environments that are too hazardous for humans, or too difficult to get to." They use hydraulic bellows to execute advanced maneuvers, including jumping:
High-tech spider for hazardous missions (via JWZ)
With its long extremities, the spider has a range of ways to get around. Some models can even jump. This is possible using hydraulically operated bellows drives that serve as joints and keep limbs mobile. With no muscles to stretch their legs, these creatures build up high levels of body pressure that they then use to pump fluid into their limbs. Shooting fluid into the legs extends them. “We took this mobility principle and applied it to our bionic, computer-controlled lightweight robot. Its eight legs and body are also fitted with elastic drive bellows that operate pneumatically to bend and extend its artificial limbs,“ explains Dipl.-Ing. Ralf Becker, a scientist at IPA. The components required for locomotion, such as the control unit, valves and compressor pump, are located in the robot‘s body; the body can also carry various measuring devices and sensors, depending on the application at hand. Hinges interoperate with the bellows drives so that the legs can move forward and turn as needed. Diagonally opposed members move simultaneously, too. Bending the front pairs of legs pulls the robotic spider‘s body along, while stretching the rear extremities pushes it.